The need to cool certain structure arises in many applications. In particular applications, it is desired to cool a structure to a substantially uniform and relatively low temperature. One example of such an application is cooling of the optical elements in a forward looking infrared radar (FLIR) turret. Such devices are often maintained at relatively high temperatures while waiting to be used, due to the ambient environment. However, it is often desirable to cool these optical elements to a temperature on the order of −50° C. during operation. Further, it is desirable that this temperature be relatively uniform throughout the optical elements to avoid deformation in the element and any associated degradation in the optical performance of the optical element. Other structural devices may also need to be cooled to a relatively low and uniform temperature, such as electronic devices.
Conventional approaches at cooling elements in a FLIR turret have involved blowing air either over the optical element or through passageways within the optical element. This approach may be useful in certain instances; however, when the desired temperature to which the optical element is to be cooled is less than the ambient air, such an approach will not be satisfactory. Further, non-uniform temperature distributions may result as the air being blown over the optical element is partially heated by the optical element.